282 KELLOGG AND BELL 



individuals, with both middle pairs fused. Class C : 3 in- 

 dividuals, with left middle pair fused. Class D : 3 indi- 

 viduals, with right middle pair fused ; 4 individuals, miscella- 

 neous. 



While most of these lots are small and therefore are not 

 necessarily (although possibly) fair indicators of the actual con- 

 dition of the variation frequencies of the species in the given 

 locality, they do pretty certainly show that the condition exist- 

 ing in the species at Stanford, namely, a dominance of the variety 

 with both middle pairs of spots fused, does not exist throughout 

 the range of the species. For example, in the series of 405 

 individuals from Santa Rosa the i2-spots-free form occurs twice 

 as often as the form with middle pairs fused. Dominance or 

 modality of the form with all spots free is also shown by the 

 series from Mountain View, and that from Stevens Creek. On 

 the contrary the condition shown by the Stanford series is also 

 shown by the lot from Oakland, lot from Arcata, that from 

 Menlo Park and the very small lot from Pacific Grove. What 

 significance these conditions have for us is obviously not clear. 

 But they indicate that if natural selection is determining the 

 dominance of the form with fused spot at Stanford, the agents 

 in this selection (in as far as the selection is actually based on 

 the color pattern) which can hardly be any others than birds, 

 toads, lizards, predaceous and parasitic insects, show curiously 

 different eyesight in different localities in California. On the 

 other hand it is quite as obvious that these varying conditions 

 of dominance throw no light on the causal factors in what we 

 have called the determinate variation of the species. If these 

 factors at Stanford induce a variation tending toward fusion of 

 the spots, such factors must be assumed to be much less effec- 

 tive at Santa Rosa, 75 miles away. We can only say that our 

 belief in the unknown factors of variation (which comes to say- 

 ing, the unknown factor in evolution) is only strengthened by 

 the anomalous conditions shown by the variation in these scat- 

 tered lots of Diabrotica soror. 



Variation in the Abdominal and Face Markings of Vespa sp. 

 (Yellow Jacket). In a lot of 496 individuals of Vespa sp., a 

 yellow jacket, collected in October and November, 1901, at 



